Doctor's Office
===============

A doctor's office needs software for scheduling appointments. It
is a large practise with 10 to 15 doctors and several thousand
patients. Patients can make an appointment with a doctor, and
all appointments last 1 hour. Doctors schedule blocks of time
when they are available for appointments. Each patient has a
primary doctor. If their primary doctor is available on the hour
and day when they wish to book they must see them; otherwise,
they can see any doctor. A patient may cancel an appointment,
but if they cancel more than 10, they are no longer allowed to
book appointments (ever!). Doctors can cancel a block of time
when they had said they were available; any patients who had
appointments during that block get rescheduled at the earliest
possible time, regardless of which doctor they get.